1) If you installed the first time at that free host I would say most of these hosts offer restricted services, and base-dir restrictions are activated for sure because of security reasons
you can find information about that in their documentations
if this happens at the free hoster, I would say do not use it
why you don't install a second WP in a subdirectory of your site, using different table-prefixes there ?
So you will have the same conditions (nearly) for test and active blog
you will never be able to have a free host working the same way your main installations are working
2) concerning comments:
I would not say that plugins don't work with Suffusion. I have NEVER seen a plugin which worked with other themes but explicitely not with Suffusion
Why don't you set some settings for comments? New comments must be activated by the webmaster and will not shine up in your
websites
Use comment-moderation and set the spammers to the blacklist
doing so, you will not need special plugins.
I also do not see that you must delete all commentspams manually. You can delete them at once.
Checkt that one checkbox and take the action "delete"
but this are WP related and not theme related questions ;?)